JP3600360B2 - Servo valve zero adjustment device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a zero adjustment device for a servo valve used in a large-scale vibration test device, an electric / hydraulic shaker, an automobile crash test device, and the like.
[0002]
[Prior art]
FIG. 6 shows a schematic configuration of a conventional servo valve zero adjustment device.
[0003]
As shown in FIG. 6, the manifold 301 is provided with a pair of servo valves 101 and 201 in parallel. In the servo valves 101 and 201, four spools 103 and 203 are integrally formed on movable shafts 102 and 202, and spool driving units 104 and 204 and servo valve nulling units 105 and 205 are mounted on shaft ends. It is configured. Then, the hydraulic pressure supply passage 106, 206 _{(P S)} is connected from a hydraulic source (not shown) in the respective servo valves 101 and 201, the hydraulic return channel 107 and 207 (R) is connected. The control ports C ₁ and C ₂ of the servo valve 101 are connected to hydraulic supply / discharge paths 108 and 109, while the control ports C ₁ and C ₂ of the servo valve 201 are connected to hydraulic supply / discharge paths 208 and 209. Then, the hydraulic supply / discharge path 108 and the hydraulic supply / discharge path 208 join as a hydraulic supply / discharge path 302, and the hydraulic supply / discharge path 109 and the hydraulic supply / discharge path 209 join as a hydraulic supply / discharge path 303.
[0004]
The hydraulic pressure supply and discharge passage 302 is connected to the supply and discharge port _{P 1} of the vibrator 304, a hydraulic supply and discharge passage 303 is connected to the supply and discharge port _{P 2,} the pressure difference of the hydraulic supply and discharge passage 302, 303 A differential pressure detector 305 for detecting is provided. Further, a displacement detector 306 is mounted on the vibrator 304, and the displacement detector 306 outputs a detection result to a servo system controller 307. The servo system controller 307 receives an input command. The drive of the spool drive units 104 and 204 of the servo valves 101 and 201 can be controlled based on the value and the shaker displacement signal from the displacement detector 306.
[0005]
As described above, in the vibration exciter 304, a plurality of (two in this embodiment) servo valves 101 and 201 are used in parallel in order to meet demands for high output and high responsiveness. By the way, in the servo valves 101 and 201 used in parallel in this way, it is necessary to perform zero adjustment. The zero adjustment is an operation of setting the spool by moving the spool to a mechanical zero position in a state where the hydraulic pressure is increased.
[0006]
In general, even if the pressure of the servo valve is zero-adjusted by itself depending on the mounting posture or the like, “zero” may be shifted or “zero” may be shifted by use. Therefore, when the equipment using the servo valve is delivered, zero adjustment is performed at the time of periodic inspection. In particular, when a large number of high-output, high-response vibrators are driven simultaneously, the energy required for the driving becomes enormous, and therefore a hydraulic power source system in which pressure is accumulated in an accumulator or the like is often used. Further, in order to reduce the output waveform distortion of the vibrator, a servo valve spool having "zero wrap" is used. Therefore, if the spool is not properly adjusted to zero, unnecessary leakage may occur, and the accumulated energy alone may be insufficient.
[0007]
For example, in the conventional servo valve zero adjustment device, as shown in FIG. 6, the command value signal input to the servo system controller 307 is “zero”, and the shaker displacement signal from the displacement detector 306 is also “zero”. And the spool 103 is + Δx and the spool 203 is −Δx mechanically in the X-axis direction even when “zero” is input as a drive control signal to the spool drive units 104 and 204 of the servo valves 101 and 201. If it is shifted, a leak occurs, but the shaker 304 remains stationary.
[0008]
With such a structure, in the conventional servo valve zero-adjustment device, the zero-adjustment includes the control system and the differential pressure between the supply / discharge ports P ₁ and P ₂ of the vibrator 304 is applied to the differential pressure detector 305. The servo valve zero adjustment units 105 and 205 adjust the detection result to zero.
[0009]
[Problems to be solved by the invention]
However, in the above-described conventional servo valve zero adjustment device, since the zero adjustment is performed with the control system closed, it is checked whether the spools 103 and 203 are mechanically at the "zero" position. I can't. Further, since the servo valves 101 and 201 are connected to each other by the hydraulic circuit, there is a problem that it takes a long time to perform the adjustment because they affect each other. Furthermore, it is difficult to zero-adjust the plurality of servo valves 101 and 201 at the same time, and only a skilled worker can do so, which increases the burden on one worker and causes heavy labor. there were.
[0010]
An object of the present invention is to solve such a problem, and an object of the present invention is to provide a zero adjustment device for a servo valve which improves reliability, speed, and workability of a zero adjustment operation.
[0011]
[Means for Solving the Problems]
A servo valve zero-adjustment device according to a first aspect of the present invention for achieving the above object includes a plurality of servo valves disposed in parallel between a hydraulic device and a hydraulic supply / discharge source for operating the hydraulic device. A switching valve interposed in a hydraulic supply / discharge path between the hydraulic device and the servo valve for connecting / disconnecting the hydraulic supply / discharge path; and a hydraulic supply / discharge between the switching valve and the servo valve. A differential pressure detector mounted on a road to detect a differential pressure of the hydraulic supply / discharge path, and zero adjustment means for controlling a zero adjustment section of the servo valve based on a detection result of the differential pressure detector, All of the hydraulic supply / discharge paths are cut off by the switching valve, and the zero adjustment section controls the zero adjustment section of the servo valve.
According to a second aspect of the present invention, there is provided a zero-adjustment device for a servo valve according to the first invention, further comprising an indicator for displaying a detection result of the differential pressure detector. The zero adjustment part of the servo valve is manually adjusted by the differential pressure displayed on the display.
Furthermore, a zero-adjustment device for a servo valve according to a third invention for achieving the above object is the zero-adjustment device according to the first or second invention, wherein the switching valve is provided in a substantially vertical direction of a hydraulic supply / discharge passage. A switching valve main body which is extended and is rotatably supported, the switching valve main body has a communication hole through which oil opens in a direction in which the hydraulic supply / discharge passage extends, and the switching valve is provided with the switching valve. The hydraulic supply / discharge path is connected / disconnected by rotation of the main body.
[0012]
Therefore, when performing zero adjustment of a plurality of servo valves arranged in parallel, the switching valve disconnects the hydraulic supply / discharge path, so that the servo valve is isolated from the hydraulic equipment, and the differential pressure detector detects the servo pressure. The zero adjustment control means controls the zero adjustment part of the servo valve based on the detection result of the differential pressure detector while detecting the differential pressure of the hydraulic supply / discharge path from the valve.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0014]
In order to operate hydraulic equipment such as a vibrator, a plurality of servo valves are arranged in parallel between the hydraulic equipment and a hydraulic supply / discharge source. The zero adjustment is performed on a plurality of servo valves. That is, a switching valve for connecting / disconnecting the hydraulic supply / discharge path is interposed in the hydraulic supply / discharge path between the hydraulic device and the plurality of servo valves. Also, in this hydraulic supply / discharge path between the hydraulic device and the plurality of servo valves, a differential pressure detector is mounted on the hydraulic supply / discharge path of the servo valve with respect to the switching valve. The differential pressure between the hydraulic supply path and the hydraulic discharge path of the servo valve can be detected. The zero-tone control device can control the zero-tone part of the servo valve based on the detection result of the differential pressure detector.
[0015]
Therefore, when zero adjustment of a plurality of servo valves arranged in parallel is performed, the switching valve disconnects the hydraulic supply / discharge path, so that each servo valve is isolated from the hydraulic equipment. In this state, while the differential pressure detector detects the differential pressure between the hydraulic pressure supply path and the hydraulic pressure discharge path from the servo valve, the zero-gating control device determines the zero-adjustment part of the servo valve based on the detection result of the differential pressure detector. Control. In this case, in the manual adjustment operation, the zero adjustment portion of the servo valve is adjusted so that the detection value becomes 0 while observing the detection result of the differential pressure detector. In the automatic adjustment operation, the detection result of the differential pressure detector is adjusted. The signal is taken out as an electric signal, and the zero adjustment controller adjusts the zero adjustment part of the servo valve based on the detection signal.
[0016]
In this way, the zero adjustment of the plurality of servo valves arranged in parallel can be performed by switching off the hydraulic supply / discharge path and setting each servo valve to an isolated state unaffected by the hydraulic equipment. In addition, the adjustment can be performed quickly and quickly, and even a non-skilled person can easily perform the zero adjustment workability.
[0017]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
FIG. 1 shows a schematic configuration of a servo valve zero adjustment device according to an embodiment of the present invention. FIGS. 2 and 3 are cross-sectional views of a switching valve applied to the servo valve zero adjustment device of the embodiment. FIG. 2 shows the communication state of the switching valve, and FIG. 3 shows the shut-off state of the switching valve.
[0019]
In the servo valve zero adjustment device of the present embodiment, as shown in FIG. 1, a pair of servo valves 11 and 21 are provided in a manifold 31 in parallel. In the servo valves 11 and 21, four spools 13 and 23 are integrally formed on the movable shafts 12 and 22, and spool driving units 14 and 24 and servo valve nulling units 15 and 25 are mounted on shaft ends. It is configured. Then, the hydraulic pressure supply passage 16, 26 _{(P S)} is connected from a hydraulic source (not shown) in the respective servo valves 11 and 21, the hydraulic return channel 17 and 27 (R) is connected. The control ports C ₁ , C ₂ of the servo valve 11 are connected to hydraulic supply / discharge paths 18, 19, while the control ports C ₁ , C ₂ of the servo valve 21 are connected to hydraulic supply / discharge paths 28, 29. The hydraulic supply / discharge path 18 and the hydraulic supply / discharge path 28 join as a hydraulic supply / discharge path 32, and the hydraulic supply / discharge path 19 and the hydraulic supply / discharge path 29 join as a hydraulic supply / discharge path 33.
[0020]
Then, the hydraulic supply and discharge passage 32 is connected to the supply and discharge port P ₁ of the vibrator 34, a hydraulic supply and discharge passage 33 is connected to the supply and discharge port P _2. Further, in the hydraulic supply and discharge passage 18, 19 connected to the control port _C 1, _{C 2} of the servo valve 11, switching valve 41 disconnects the hydraulic supply and discharge passage 18, 19 is interposed. On the other hand, to the hydraulic supply and discharge passage 28 and 29 connected to the control port _C 1, _{C 2} of the servo valve 21, switching valve 51 which disconnects the hydraulic supply and discharge passage 28, 29 is interposed. A differential pressure detector 42 is mounted on the hydraulic supply / discharge passages 18 and 19 between the servo valve 11 and the switching valve 41, while the hydraulic supply / discharge passage 28 between the servo valve 21 and the switching valve 51 is provided. , 29 are provided with a differential pressure detector 52, and the differential pressure detectors 41, 51 can detect the differential pressure between the hydraulic supply path and the hydraulic discharge path of the servo valves 11, 21.
[0021]
These differential pressure detectors 42 and 52 are connected to zero-tone control devices 43 and 53, respectively, and input the detection results. Based on the detection signals of the differential pressure detectors 41 and 51, servo valves are provided. The drive of the servo valve zero-adjustment units 15 and 25 is controlled, and the spool drive units 14 and 24 drive the spools 13 and 23 to perform zero adjustment. Reference numeral 36 denotes a displacement detector 36 mounted on the vibrator 34.
[0022]
Here, the above-described switching valves 41 and 51 will be described. However, since both have almost the same structure, only one of the switching valves 41 will be described. In the switching valve 41, as shown in FIG. 2, a mounting hole 61 is formed in the manifold 31 so as to intersect the hydraulic supply / discharge passages 18, 19, and a cylindrical switching valve body 62 is formed in the mounting hole 61. It is fitted rotatably. The switching valve body 62 has a pair of communication holes 63 and 64 for communicating the hydraulic supply / discharge passages 18 and 19, and a substrate 65 and an operation knob 66 are integrally fixed at one end thereof. 65 can be fixed to the manifold 31 by bolts 67. A seal member 68 for preventing leakage of pressure oil is mounted between the mounting hole 61 and the switching valve main body 62. Further, a drain line 69 for depressurizing is formed at the tip end of the mounting hole 61 to prevent the switching valve main body 62 from being pushed out of the mounting hole 61 by the pressure oil.
[0023]
Therefore, as shown in FIG. 2, when the switching valve 41 is opened, the hydraulic supply / discharge passages 18 and 19 are communicated by the communication holes 63 and 64 of the switching valve main body 62, and the supply and discharge of the pressure oil can be performed. Become. Then, by removing each bolt 67 and turning the switching valve main body 62 approximately 90 degrees by the operation knob 66 to “close”, and fixing the substrate 65 again by each bolt 67 in this state, as shown in FIG. Meanwhile, the hydraulic supply / discharge passages 18 and 19 are shut off by the switching valve main body 62, and supply / discharge of pressure oil is disabled.
[0024]
When zero adjustment is performed by the servo valve zero adjustment device of the present embodiment, as shown in FIG. 1, the switching valves 41 and 51 are closed and the hydraulic supply / discharge passages 18, 19, 28 and 29 are closed. Accordingly, the servo valves 11 and 21 are isolated from the vibrator 34. In this state, the differential pressure detectors 42 and 52 detect the differential pressures ΔP ₁ and ΔP ₂ of the hydraulic supply / discharge passages 18 and 19, 28 and 29 between the servo valves 11 and 21 and the switching valves 41 and 51. , And outputs the detection results to the zero-tone control devices 43 and 53. The zero-tone control devices 43 and 53 take out the detection results (differential pressures ΔP ₁ and ΔP ₂ ) of the differential pressure detectors 42 and 52 as electric signals, and based on the electric signals, set the servo valve zeros of the servo valves 11 and 21 to zero. The control units 15 and 25 are driven and controlled. That is, the servo valve zero adjusting units 15 and 25 drive the respective spools 13 and 23 by the spool driving units 14 and 24 to perform zero adjustment.
[0025]
Although the zero-tone control devices 43 and 53 automatically drive-control the servo valve zero-tone parts 15 and 25 based on the electric signals detected by the differential pressure detectors 42 and 52, when the operator performs a manual adjustment operation, An indicator is provided for displaying the differential pressures ΔP ₁ , ΔP ₂ as the detection results of the differential pressure detectors 42, 52, and the operator can use the display to display the differential pressure ΔP as a detection value of the differential pressure detectors 42, 52. ₁ and ΔP ₂ , and the servo valve zero-adjusting units 15 and 25 may be manually adjusted so that the differential pressures ΔP ₁ and ΔP ₂ become zero.
[0026]
The zero adjustment of the plurality of servo valves 11 and 21 arranged in this manner is performed by setting the hydraulic supply / discharge passages 18, 19, 28 and 29 to the disconnected state by the switching valves 41 and 51 and setting the respective servo valves 11 and 21 to the vibrator 34. It is possible to perform the zero adjustment operation accurately and promptly, and it is possible to easily perform the zero adjustment work even if it is not an expert.
[0027]
In this embodiment, the switching valves 41, 51 are provided corresponding to the hydraulic supply / discharge paths 18, 19, 28, 29, but the invention is not limited to this configuration. 4 and 5 show cross sections of another switching valve.
[0028]
As shown in FIG. 4 , in the switching valve 71, mounting holes 72a and 72b are respectively formed in the manifold 31 so as to intersect the hydraulic supply and discharge passages 18 and 19, and the mounting holes 72a and 72b are formed in cylindrical shapes. The switching valve bodies 73a, 73b are rotatably fitted. The switching valve bodies 73a and 73b are formed with a pair of communication holes 74a and 74b that communicate the hydraulic supply and discharge passages 18 and 19, and have substrates 75a and 75b and operation knobs 76a and 76b integrally formed at one end. The substrates 75a and 75b are fixed to the manifold 31 by bolts 77a and 77b. Seal members 78a and 78b for preventing leakage of pressure oil are mounted between the mounting holes 72a and 72b and the switching valve bodies 73a and 73b, and a pressure release drain line is provided at the tip of the mounting holes 72a and 72b. 79 are formed.
[0029]
Therefore, when the operation knobs 76a and 76b of the switching valve 71 are opened, the hydraulic supply / discharge passages 18 and 19 are communicated by the communication holes 74a and 74b of the switching valve bodies 73a and 73b, and the supply of the pressure oil is performed. Expulsion becomes possible. Then, the bolts 77a, 77b are removed, and the switching valve bodies 73a, 73b are turned approximately 90 degrees by the operation knobs 76a, 76b to "close", whereby the hydraulic supply / discharge paths 18, 19 are connected to the switching valve body 73a. , 73b, and the supply and discharge of the pressure oil is disabled. In this way, in the switching valve 71, each of the hydraulic supply / discharge passages 18, 19 can be opened and closed independently.
[0030]
As shown in FIG. 5 , in the switching valve 81, a mounting hole 82 is formed in the manifold 31 so as to intersect the hydraulic supply / discharge passages 18, 19, 28, 29, and the mounting hole 82 has a cylindrical shape. The switching valve body 83 is rotatably fitted. The switching valve body 83 has communication holes 84a, 84b, 84c, 84d communicating with the hydraulic supply / discharge passages 18, 19, 28, 29, and a substrate 85 and an operation knob 86 at one end. The board 85 is fixed to the manifold 31 by bolts 87. Further, a seal member 88 for preventing leakage of pressure oil is mounted between the mounting hole 82 and the switching valve main body 83, and a pressure release drain line 89 is formed at a tip end of the mounting hole 82.
[0031]
Therefore, when the switching knob 81 is opened by the operation knob 86, the hydraulic supply / discharge passages 18, 19, 28, 29 are communicated by the communication holes 84a, 84b, 84c, 84d of the switching valve body 83, and the hydraulic oil Can be supplied and discharged. Then, by removing each bolt 87 and turning the switching valve main body 83 approximately 90 degrees by the operation knob 86 to “close”, the hydraulic supply / discharge passages 18, 19, 28 and 29 are shut off by the switching valve main body 83. It becomes a state, and supply and discharge of pressure oil become impossible. In this way, the switching valve 81 can simultaneously open and close the hydraulic supply / discharge passages 18, 19, 28, and 29.
[0032]
【The invention's effect】
As described above in detail with reference to the embodiments, according to the servo valve zero adjustment device of the present invention, a plurality of servo valves are provided between the hydraulic device and the hydraulic supply / discharge source to operate the hydraulic device. A switching valve, which is disposed in parallel, connects and disconnects the hydraulic supply / discharge path to / from a hydraulic supply / discharge path between the hydraulic device and the servo valve, and a hydraulic supply / discharge path between the switching valve and the servo valve. Since the differential pressure detector for detecting the differential pressure of the hydraulic supply / discharge path is mounted on the hydraulic pressure supply / discharge path, and the zero adjustment control means controls the zero adjustment portion of the servo valve based on the detection result of the differential pressure detector, With the switching valve, the hydraulic supply / discharge path is disconnected and each servo valve can be zero-adjusted as an isolated state unaffected by hydraulic equipment. This zero-adjustment operation can be performed accurately and quickly. It is easy for non-experts to perform zero adjustment workability. Can. In this way, the reliability, speed, and workability of the zero adjustment operation can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a servo valve zero adjustment device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a communication state of a switching valve applied to the servo valve zero-adjustment device of the present embodiment.
FIG. 3 is a sectional view showing a shut-off state of a switching valve applied to the servo valve zero-adjustment device of the embodiment.
FIG. 4 is a sectional view of another switching valve.
FIG. 5 is a sectional view of another switching valve.
FIG. 6 is a schematic configuration diagram of a conventional zero adjustment device for a servo valve.
[Explanation of symbols]
11, 21 Servo valve 13, 23 Spool 14, 24 Spool drive unit 15, 25 Sabo valve zero adjustment unit 18, 19, 28, 29 Hydraulic supply / discharge path 34 Vibrators 41, 51 Switching valves 42, 52 Differential pressure detector 43 , 53 Zero-tone controller

Claims (3)

A plurality of servo valve zero-adjustment devices arranged in parallel between a hydraulic device and a hydraulic supply / discharge source to operate the hydraulic device, the hydraulic device including a hydraulic supply / discharge passage between the hydraulic device and the servo valve. A switching valve mounted on and off the hydraulic supply / discharge path, a differential pressure detector mounted on the hydraulic supply / discharge path between the switching valve and the servo valve to detect a differential pressure of the hydraulic supply / discharge path, Zero adjustment means for controlling a zero adjustment part of the servo valve based on the detection result of the differential pressure detector, wherein the switching valve shuts off all hydraulic supply / discharge paths, and the servo adjustment is performed by the zero adjustment means. A zero adjustment device for a servo valve, which controls a zero adjustment part of the valve. 2. The zero-adjustment device according to claim 1, further comprising a display for displaying a detection result of the differential pressure detector, wherein the zero-adjustment part of the servo valve is manually adjusted by the differential pressure displayed on the display. A zero adjustment device for a servo valve. 3. The zero-adjustment device according to claim 1, wherein the switching valve includes a switching valve main body that extends in a substantially vertical direction of a hydraulic supply / discharge passage and is rotatably supported. A servo valve zero adjustment device, comprising: a communication hole through which oil is opened in the direction in which the supply / discharge path extends, and wherein the switching valve disconnects / connects a hydraulic supply / discharge path by rotation of the switching valve body.

Images